Investigating the impact of some habitat characteristics on distribution of Stachys pilifera benth using the BMLR model in Iran

Abstract

Stachys pilifera is an endemic plant to Iran. The main purpose of this study was to investigate the impacts of some habitat characteristics on the distribution of S. pilifera using the BMLR model in Kohgiluyeh and Boyer-Ahmad Province, Iran. Tow transects were randomly established in each region. 10 quadrats sized 1 × 1 m2 were established along the transect. In each plot, canopy cover (%) of S. pilifera was recorded. 25 soil samples were gathered in the region to evaluate soil characteristics. The associated pixel of each plot was extracted and added to a prepared spreadsheet of a field database. The data gathered from experiments were fed into the computer item by item according to their own values. To determine the effect of environmental factors on the distribution of S. pilifera species, the researchers run a set of backward multiple linear regressions. The results of MLR to investigate the significance of was not significant (P-Value >0.05). Then the most insignificant term in the first run (silt) is removed and the operation run again. After removing silt, the results of the BMLR model are seen by considering the effect of other factors, and some of terms are insignificant again. The process is continued step by step to the point that there are only significant terms. Results showed that the effects of rain, sand, P, Fe, Zn, Mn, and evaporation on the distribution of S. pilifera species were significant. Rain, P, and Fe have positive effects (positive coefficient), while sand, Zn, Mn, and evaporation have negative effects (negative coefficient). Results showed that the BMLR appropriately modeled the canopy cover of S. pilifera based on RMSE, R2, and, which were 0.999, 0.998, and 2.1395, respectively.